The present invention relates in general to absorbent pads, and in more particular, to a method of forming a generally leak-proof peripherally sealed absorbent pad, such as a compression sponge for wound care, using a precut overlay.
Absorbent pads are known in the medical field. For example, U.S. Pat. No. 6,162,960, entitled COMPRESSION SPONGE FOR WOUND CARE, describes a highly absorbent pad that is ideally suited for use as a compression sponge for wound care. Absorbent pads, such as the one described in U.S. Pat. No. 6,162,960 have many uses. For example, such pads can be used for patient recovery from tumescent liposuction procedures involving infusion of relatively large quantities of liquid which must then exit incision sites. In such liposuction procedures, an elastic garment may be worn over an absorbent medium, but non-uniform distribution of absorbed liquid drainage in such cases can cause bruising of skin tissue.
The wound care sponge described in U.S. Pat. No. 6,162,960 includes a highly absorbent generally uniform bibulous layer which operates as a wick to absorb, generally uniformly distribute therethrough, and retain liquid whereby the uniform liquid distribution throughout the entire layer provides uniform pressure distribution of any externally applied pressure on the pad. A liquid-permeable sheet, such as a non-interacting liquid-permeable paper product is disposed on the surface of the bibulous layer to interface with the wound site. A liquid-impermeable sheet with wrap-around edges prevents leakage of liquid from the pad.
A typical method of manufacture of absorbent pads such as the one described in U.S. Pat. No. 6,162,960 involves using a large roller to assemble the layers of the pad. Layers are formed as follows: (1) a sheet of liquid-impermeable material; (2) precut pads of the bibulous material are disposed on the sheet of liquid-impermeable material; and (3) a sheet of liquid-permeable material is then disposed on the precut pads of the bibulous material. The three layers are then assembled using the large roller. After being assembled using the large roller, the edges of the liquid-impermeable material are manually wrapped around the pad to form a frame around the liquid-permeable material. The edges of the liquid-impermeable material are then sealed to the liquid-permeable material. Such a manual process is time-consuming and costly.
Thus, a need exists for a more efficient, less labor intensive method of forming a generally leak-proof peripherally sealed absorbent pad.
In addition to the problems described above, many prior art absorbent pads are sealed only on two or three sides. Such pads are not sufficient for many applications. In particular, such pads are generally not suitable for uses in which the pad will be in a vertical orientation.
Thus, there is also a need for a more efficient, less labor intensive method of forming a generally leak-proof peripherally sealed absorbent pad that is sealed around all of the edges of the pad.